Ureteral Stent

ABSTRACT

Disclosed herein is ureteral stent. The ureteral stent includes a proximal end, a distal end, and a middle portion. The proximal end includes a retention feature having a coiled shape. The distal end is opposite the proximal end. The middle portion is between the proximal end and the distal end.

BACKGROUND Field of the Invention

The invention relates to a ureteral stent and more specifically relatesto a comfort ureteral stent.

Brief Description of Prior Developments

A ureter is a tubular passageway in the body that conveys urine from akidney to a bladder. Ureteral stents are used to facilitate urinarydrainage from the kidney to the bladder in patients having a ureteralobstruction or injury, or to protect the integrity of the ureter in avariety of surgical manipulations. Ureteral stents are typically about30 cm long, hollow catheter-like devices made from a polymer and placedwithin the ureter with a distal end residing in the kidney and aproximal end residing in the bladder.

Accordingly, there is a need to provide improved and reliable ureteralstent configurations that are configured for increased patient comfort.

SUMMARY

In accordance with one aspect of the invention, a ureteral stent isdisclosed. The ureteral stent includes a proximal end, a distal end, anda middle portion. The proximal end includes a retention feature having acoiled shape. The distal end is opposite the proximal end. The middleportion is between the proximal end and the distal end.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the invention are explainedin the following description, taken in connection with the accompanyingdrawings, wherein:

FIG. 1 is a partial perspective view of ureteral stent (within the bodyof a patient) incorporating features of the invention;

FIG. 2 is another perspective view of the ureteral stent shown in FIG.1;

FIG. 3 is a section view of the indicated section line in FIG. 2;

FIG. 4 is an enlarged view of the indicated portion in FIG. 2;

FIG. 5 is a partial view of a tail portion of the ureteral stent shownin FIG. 1;

FIGS. 6 and 7 are perspective views of alternate configurations of afloating tip portion of the ureteral stent shown in FIG. 1;

FIG. 8 is a perspective view of another example ureteral stentincorporating features of the invention;

FIG. 9 is a section view of the indicated section line in FIG. 8;

FIG. 10 is an alternate embodiment of the proximal end shown in FIG. 8;

FIG. 11 is a perspective view showing a fixture corresponding to theproximal end shown in FIG. 10;

FIG. 12 is another alternate embodiment of the proximal end shown inFIG. 8;

FIG. 13 is another alternate embodiment of the proximal end shown inFIG. 8;

FIG. 14 is a perspective view of another example ureteral stentincorporating features of the invention;

FIG. 15 is a section view of the indicated section line in FIG. 14;

FIG. 16 is a top view of the ureteral stent shown in FIG. 14;

FIGS. 17-20 are alternate exterior valve configurations according tovarious embodiments of the ureteral stent; and

FIGS. 21, 22 are alternate proximal portion configurations according tovarious embodiments of the ureteral stent.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown a partial perspective view of aureteral stent 10 incorporating features of the invention. Although theinvention will be described with reference to the exemplary embodimentsshown in the drawings, it should be understood that the invention can beembodied in many alternate forms of embodiments. In addition, anysuitable size, shape or type of elements or materials could be used.

The ureteral stent 10 comprises a tubular member 12 having a proximalend 14, an opposite distal end 16, and a middle portion 18 between theproximal end 14 and the distal end 16. The proximal end 14 is configuredto be placed within the renal pelvis 20 of the kidney 22. The distal end16 is configured to be placed within the bladder 24.

Referring now also to FIG. 2, the proximal end 14 comprises a coiledconfiguration (or shape) having a conical spiral shape 26. The conicalspiral shape 26 extends away from the middle portion 18 such that thediameter of the conical spiral shape 26 increases as the shape extendsaway from the middle portion and a first open end 28 of the stent 10 isat substantially the largest diameter portion of the conical spiralshape 26.

The conical spiral shape 26 of the proximal end 14 is configured toallow for anchoring of the proximal end 14 within the renal pelvis. Thisprovides a retention mechanism which reduces the contact force placed onthe pelvis wall (of the renal pelvis 20) by providing increased surfacearea of contact between the proximal end and the pelvis wall whencompared to conventional configurations.

The middle portion 18 comprises side holes (or openings) 30 extendingthrough a wall of the tubular member. Referring now also to section view3-3, the side holes 30 are configured to have smooth edges (or smoothopening surfaces) 32. The smooth edges may be provided by any suitablemachining or fabrication operation capable of rounding the edges (suchas by providing a fillet, blend, corner radius, or rounded corner, atthe edges 32). According to various exemplary embodiments, the smoothingprocess may include a punch process wherein during the punching thepolymer is melted removing any sharp edges. Also, the edges can be postoperatively melted with a hot air, flame or hot tool, for example. Thesmooth edges may be provided any suitable edge areas of the holes 32between an inside diameter and an outside diameter of the tubularmember.

It should be noted that although various figures illustrate the stent 10as comprising four side holes 30 at the middle portion 18, one skilledin the art will appreciate that the various exemplary embodiments arenot necessarily so limited and that alternate embodiments may compriseany suitable number of side holes. For example in some embodiments, thestent may comprise one or more side holes, in other embodiments thestent may comprise five or more side holes, and it should be understoodthat any number of side holes may be provided. Additionally, the sideholes 30 may be provided at any one, or combination of, the proximal end14, the distal end 16, and/or the middle portion 18 (with any suitablenumber of side holes at each end 14, 16 or the middle portion 18),including at retention portions or other shaped features of the ends.

As the urethra elongates and contracts with bladder voiding action, thismovement results in the ureter rubbing against the edges 32 of the holes30. This “smooth” hole configuration is configured to reduce irritationand patient pain. In addition to the smooth aspect of the hole edgeconfiguration for patient comfort, the smooth edges are also provided toreduce turbulence of urine flow (as it promotes encrustation). Thissmooth edge configuration of the holes reduces turbulence during flowdown the ureter whether it is gravity feed or the peristaltic action ofthe ureter itself. Additionally, the position of the holes may play arole in urine reflux (discussed further below).

According to various exemplary embodiments, the stent 10 may furthercomprise an exterior reflux skirt 34 and/or an interior reflux valve 36between the middle portion 18 and the distal end 16. The exterior refluxskirt 34 surrounds a portion of the tubular member with a general coneshape and is configured to minimize exterior reflux flow. The interiorreflux valve 36 is configured to provide one way flow through thetubular member (see arrow 38). According to various exemplaryembodiments, the interior reflux valve 36 may be a duck bill valve,however in alternate embodiments, any suitable type of valve allowingfor one way flow may be provided, such as a check valve, for example.

The distal end 16 comprises a tail portion (or tip portion) 40configured to be received within the bladder proximate a zone or regioncalled the “Trigon”. The Trigon has copious nerve endings signaling theneed to void the bladder and when voiding is complete. Contact with thetrigon zone causes much of the patient's discomfort. The tail portion 40comprises a foam material and is configured such that the tail portion“floats” in water/urine in the bladder (with the foam having a specificgravity <1.0, for example) minimizing (or eliminating) contact with thetrigon when any urine is present. Although the tail portion is describedabove as having a foam material, one skilled in the art will appreciatethe exemplary embodiments are not necessarily so limited, and thatalternate embodiments may comprise any suitable material configured tofloat in the bladder, such as configurations having “trapped” air in theside walls to achieve floating, for example.

According to various exemplary embodiments, the tail portion 40 mayfurther comprise a one-way urine flow valve 42 enabling reductions inurine reflux (urine flow back up the ureter to the kidney). Theconfiguration of the distal tail 40 including the one-way valve 42requires no additional components as it comprises a folded tube heat setfeature as shown in FIG. 5. According to various exemplary embodiments,the configuration of the one-way urine flow valve 42 may be similar tothe configuration of a duck bill valve, however a duck valve maygenerally be wider than the normal tubular outside diameter (OD) and a4-wing valve could be smaller than the OD. Multiple wing configurationsmay also apply in some embodiments. In situ, the one-way valve 42substantially eliminates reflux through the stent lumen but not exteriorto the stent.

FIGS. 6 and 7 illustrate alternate configurations of the floating tipportion. The floating tip portion 140 is similar to the tip portion 40,however in this embodiment the tip portion 140 comprises a taperedportion 142. Additionally, the floating tip portion 240 is similar tothe tip portion 40 and comprises a reflux valve 242 which is fittedwithin an end portion of the tubular member 12.

According to the various exemplary embodiments, an exterior anti-refluxfeature 34, 36 may be provided to substantially eliminate the urine flowaround the exterior of the stent. The combination of the distal valve 42within the bladder and exterior valve 36 near the midpoint of the stentand providing holes 30 having smooth low turbulence side edges 32 aboveor on the kidney side of the exterior reflux feature provides forreduction of urine reflux. Additionally, in some embodiments the distalend 16 may comprise a J-hook migration lock 44 configured to preventmigration of the stent due to patient movement.

Referring now also to FIG. 8 another embodiment of the stent is shown.In this embodiment, the stent 300 comprises a distal end 316 similar tothe distal end 16 shown in FIGS. 1, 2, and middle portion 318 similar tothe middle portion 18 shown in FIGS. 1, 2 (with holes 330 similar toholes 30 and valve 336 similar to valve 36). However, at the proximalend 314 the tubular member 312 comprises a bend portion 360 whichextends to the largest diameter portion of the spiral conical shape 326.The conical spiral shape 326 surrounds the tubular member 312 andextends towards the middle portion 318 such that the diameter of theconical spiral shape 326 decreases as the shape extends towards themiddle portion 318 and a first open end 328 of the stent 300 is atsubstantially the smallest diameter portion of the conical spiral shape326. In this embodiment, the conical spiral shape 326 is configured tolock the distal end into position, and the top portion of the conicalspiral shape (i.e. largest diameter portion) allows a spring action asureteral contracts.

Referring now also to FIG. 10, another alternate embodiment of theproximal end is shown. The proximal end 414 comprises a dual conicalspiral shape 426 having a spring region 462 and an anchor region 464.Similar to the configuration shown in FIG. 8, the tubular member 412comprises a bend portion 460. However from the bend portion, the springregion 462 of the conical spiral shape increases in a direction awayfrom the bend portion and the largest diameter portion of the spiralconical shape 426 is between the spring region 462 and the anchor region464. The conical spiral shape 426 surrounds the tubular member 412 andextends towards the middle portion 418 such that the diameter of theconical spiral shape 426 decreases as the shape extends from the springregion towards the middle portion 318 and a first open end 428 of thestent 400 is at substantially the smallest diameter portion of theconical spiral shape 426.

According to various exemplary embodiments the dual conical spring shapemay be provided with a heat set fixture comprising two conical regions562, 564 which correspond to the regions 462, 464, of the conical spiralshape 426 (see FIG. 11). However, it should be noted that the fixtureshown in FIG. 11 is merely exemplary and any suitable type of fixturemay be provided.

Referring now also to FIG. 12, another alternate embodiment of theproximal end is shown. Similar to the proximal end shown in FIG. 8, theproximal end 614 comprises a bend portion 660 and a first open end 628.However in this embodiment, the proximal end 614 comprises a coiledshape 626 which lies substantially in a plane orthogonal to the middleportion 618 of the stent 600. The coiled shape 626 surrounds the end ofthe tubular member 612 in a coiled/spiraled fashion.

Referring now also to FIG. 13, another alternate embodiment of theproximal end is shown. Similar to the proximal end shown in FIG. 8, theproximal end 714 comprises a bend portion 760 and a first open end 728.However in this embodiment, the proximal end 714 comprises a coiledsection having a general spherical or bulb-like shape 726. The coiledspherical or bulb-like shape 726 surrounds a portion at the end of thetubular member 712 of the stent 700.

Referring now also to FIG. 14 another embodiment of the stent is shown.In this embodiment, the stent 800 comprises a distal end 816 similar tothe distal end 316 shown in FIG. 8, and middle portion 818 similar tothe middle portion 318 shown in FIG. 8 (with holes 830 similar to holes330 and valve 836 similar to valve 336). However, at the proximal end814 the spiral conical shape 826 comprises a reverse spiral (see FIG.16) compared to the configuration shown in FIG. 8 (in other words, whenviewed from the top, the spiral has a ‘clockwise’ configuration fromlargest diameter to smallest diameter, whereas the configuration in FIG.8 when viewed from the top, the spiral has a ‘counter-clockwise’configuration from largest diameter to smallest diameter). Additionally,FIG. 16 illustrates (see arrows) where holes 830 are also provided onthe internal surface (i.e. surface facing the tubular member 812) of theconical spiral shape 826. However, it should be noted that the holes 830may be provided at any suitable surface portion of the conical spiralshape 826.

FIGS. 17-20 illustrate various exemplary embodiments of the exteriorreflux skirt 34 (shown in FIG. 4), however the reflux skirt (or valve)934, 934′, are configured to actuate, and in some embodiments shorten,over a narrowed portion of the tubular member 912. As the exterior valve934, 934′ shortens, it expands radially creating a larger portion of thestent to therefore block exterior liquid flow.

FIGS. 21, 22 illustrate an exemplary embodiment of a proximal portion1014 that is configured to be adjustable to fit within the renal pelvisof various patients. However, it should be noted that the adjustableportions illustrated in FIGS. 21, 22 may comprise any suitableconfiguration.

Technical effects of any one or more of the exemplary embodimentsprovide significant advantages over conventional configurations havingside holes which are typically punched or drilled through the wallresulting in a sharp edge(s). The exemplary embodiments disclosed hereinprovide a smooth hole edge configuration (providing smooth exteriorports) which reduces patient pain and provides greater comfort.

Below are provided further descriptions of various non-limiting,exemplary embodiments. The below-described exemplary embodiments may bepracticed in conjunction with one or more other aspects or exemplaryembodiments. That is, the exemplary embodiments of the invention, suchas those described immediately below, may be implemented, practiced orutilized in any combination (e.g., any combination that is suitable,practicable and/or feasible) and are not limited only to thosecombinations described herein and/or included in the appended claims.

In one exemplary embodiment, a ureteral stent comprising: a proximal endcomprising a retention feature having a coiled shape; a distal endopposite the proximal end; and a middle portion between the proximal endand the distal end.

A ureteral stent as above, wherein the middle portion comprises at leastone opening having smooth opening surfaces.

A ureteral stent as above, wherein the at least one opening comprisesrounded edges.

A ureteral stent as above, wherein the coiled shape is a spiral shape.

A ureteral stent as above, wherein the retention feature has a conicalcoiled shape.

A ureteral stent as above, wherein the coiled shape retention featurelies substantially on a plane orthogonal to the plane the middle portionlies on.

A ureteral stent as above, wherein the retention feature comprises ageneral spherical shape.

A ureteral stent as above, wherein the distal end comprises a tailportion configured to float.

A ureteral stent as above, wherein the retention feature comprises adual conical spiral shape.

A ureteral stent as above, further comprising a one-way valve betweenthe middle portion and the distal end.

A ureteral stent as above, further comprising a one-way valve at thedistal end.

A ureteral stent as above, wherein the distal end comprises a retentionfeature.

It should be understood that components of the invention can beoperationally coupled or connected and that any number or combination ofintervening elements can exist (including no intervening elements). Theconnections can be direct or indirect and additionally there can merelybe a functional relationship between components.

It should be understood that the foregoing description is onlyillustrative of the invention. Various alternatives and modificationscan be devised by those skilled in the art without departing from theinvention. Accordingly, the invention is intended to embrace all suchalternatives, modifications and variances which fall within the scope ofthe appended claims.

What is claimed is:
 1. A ureteral stent comprising: a proximal endcomprising a retention feature having a coiled shape; a distal endopposite the proximal end; and a middle portion between the proximal endand the distal end.
 2. The ureteral stent of claim 1, wherein the middleportion comprises at least one opening having smooth opening surfaces.3. The ureteral stent of claim 2, wherein the at least one openingcomprises rounded edges.
 4. The ureteral stent of claim 1, wherein thecoiled shape is a spiral shape.
 5. The ureteral stent of claim 1,wherein the retention feature has a conical coiled shape.
 6. Theureteral stent of claim 5, wherein the coiled shape retention featurelies substantially on a plane orthogonal to the plane the middle portionlies on.
 7. The ureteral stent of claim 1, wherein the retention featurecomprises a general spherical shape.
 8. The ureteral stent of claim 1,wherein the distal end comprises a tail portion configured to float. 9.The ureteral stent of claim 1, wherein the retention feature comprises adual conical spiral shape.
 10. The ureteral stent of claim 1, furthercomprising a one-way valve between the middle portion and the distalend.
 11. The ureteral stent of claim 1, further comprising a one-wayvalve at the distal end.
 12. The ureteral stent of claim 1, wherein thedistal end comprises a retention feature.